Answer:
The freezing of water into ice causes the cracks to widen because it occupy more space.
Explanation:
When the water change its state of liquid to solid state due to decrease in temperature, it contracts means occupy less space but when the temperature reaches to 4 degree Celsius, it starts to expand. When the temperature goes below 0 degree Celsius, it will cause more expansion and occupy more space that causes the cracks to widen.
Answer:
penicillin could protect mice against infection from deadly Streptococci.
Explanation:
The potential energy of the reactants is 200J.
From the energy diagram, the energy of the product formed is 350J; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.<span />
Answer:
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
Chemical equation:
Mg + HCl → H₂ + MgCl₂
24 g + 36.5 g = 2 g+ 95 g
60.5 g = 97 g
The reaction does not hold the law of conservation of mass, because it is not balanced.
Balanced chemical equation:
Mg + 2HCl → H₂ + MgCl₂
24 g + 73 g = 2 g+ 95 g
97 g = 97 g
this equation completely follow the law of conservation of mass.
